package org.asiainfo.common.core.utils.file;

import cn.hutool.core.date.DateUtil;
import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.IdUtil;
import org.asiainfo.common.core.exception.file.FileNameLengthLimitExceededException;
import org.asiainfo.common.core.exception.file.FileSizeLimitExceededException;
import org.asiainfo.common.core.exception.file.InvalidExtensionException;
import org.asiainfo.common.core.utils.StringUtils;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;
import java.nio.file.Paths;
import java.util.Date;
import java.util.Objects;

/**
 * 文件上传工具类
 *
 * @author dotor-ww
 */
public class FileUploadUtils {

    /**
     * 默认大小 50M
     */
    public static final long DEFAULT_MAX_SIZE = 50 * 1024 * 1024;

    /**
     * 默认的文件名最大长度 100
     */
    public static final int DEFAULT_FILE_NAME_LENGTH = 100;

    /**
     * 判断MIME类型是否是允许的MIME类型
     *
     * @param extension        上传文件类型
     * @param allowedExtension 允许上传文件类型
     * @return true/false
     */
    public static boolean isAllowedExtension(String extension, String[] allowedExtension) {
        for (String str : allowedExtension) {
            if (str.equalsIgnoreCase(extension)) {
                return true;
            }
        }
        return false;
    }

    /**
     * 根据文件名获取路径
     *
     * @param fileName 文件名
     * @return 路径
     * @throws IOException 错误
     */
    private static String getPathFileName(String fileName) throws IOException {
        return "/" + fileName;
    }

    /**
     * 获取文件名称
     *
     * @param file 文件
     * @return 文件名称
     */
    public static String extractFilename(MultipartFile file) {
        return StringUtils.format("{}/{}_{}.{}", DateUtil.format(new Date(), "yyyy/MM/dd"),
            FileUtil.mainName(file.getOriginalFilename()), IdUtil.fastSimpleUUID(), getExtension(file));
    }

    /**
     * 根据文件路径上传
     *
     * @param baseDir 相对应用的基目录
     * @param file    上传的文件
     * @return 文件名称
     * @throws IOException
     */
    public static String upload(String baseDir, MultipartFile file) throws IOException {
        try {
            return upload(baseDir, file, MimeTypeUtils.DEFAULT_ALLOWED_EXTENSION);
        } catch (Exception e) {
            throw new IOException(e.getMessage(), e);
        }
    }

    /**
     * 文件上传
     *
     * @param baseDir          相对应用的基目录
     * @param file             上传的文件
     * @param allowedExtension 上传文件类型
     * @return 返回上传成功的文件名
     * @throws IOException 比如读写文件出错时
     */
    public static String upload(String baseDir, MultipartFile file, String[] allowedExtension) throws IOException {
        int fileNameLength = Objects.requireNonNull(file.getOriginalFilename()).length();
        if (fileNameLength > FileUploadUtils.DEFAULT_FILE_NAME_LENGTH) {
            throw new FileNameLengthLimitExceededException("upload.filename.exceed.length", FileUploadUtils.DEFAULT_FILE_NAME_LENGTH);
        }
        assertAllowed(file, allowedExtension);
        String fileName = extractFilename(file);
        String absPath = getAbsoluteFile(baseDir, fileName).getAbsolutePath();
        file.transferTo(Paths.get(absPath));
        return getPathFileName(fileName);
    }

    /**
     * 检查文件夹是否存在 不存在则创建
     *
     * @param uploadDir 文件夹路径
     * @param fileName  文件名
     * @return File
     */
    private static File getAbsoluteFile(String uploadDir, String fileName) {
        File desc = new File(uploadDir + File.separator + fileName);
        if (!desc.exists()) {
            if (!desc.getParentFile().exists()) {
                boolean mkdirs = desc.getParentFile().mkdirs();
            }
        }
        return desc.isAbsolute() ? desc : desc.getAbsoluteFile();
    }

    /**
     * 文件大小校验
     *
     * @param file 上传的文件
     */
    public static void assertAllowed(MultipartFile file, String[] allowedExtension) {
        long size = file.getSize();
        if (size > DEFAULT_MAX_SIZE) {
            throw new FileSizeLimitExceededException("upload.exceed.maxSize", DEFAULT_MAX_SIZE / 1024 / 1024);
        }
        String fileName = file.getOriginalFilename();
        String extension = getExtension(file);
        if (allowedExtension != null && !isAllowedExtension(extension, allowedExtension)) {
            if (allowedExtension == MimeTypeUtils.IMAGE_EXTENSION) {
                throw new InvalidExtensionException.InvalidImageExtensionException(allowedExtension, extension, fileName);
            } else if (allowedExtension == MimeTypeUtils.FLASH_EXTENSION) {
                throw new InvalidExtensionException.InvalidFlashExtensionException(allowedExtension, extension, fileName);
            } else if (allowedExtension == MimeTypeUtils.MEDIA_EXTENSION) {
                throw new InvalidExtensionException.InvalidMediaExtensionException(allowedExtension, extension, fileName);
            } else if (allowedExtension == MimeTypeUtils.VIDEO_EXTENSION) {
                throw new InvalidExtensionException.InvalidVideoExtensionException(allowedExtension, extension, fileName);
            } else {
                throw new InvalidExtensionException(allowedExtension, extension, fileName);
            }
        }
    }

    /**
     * 获取给定MultipartFile对象的文件扩展名
     *
     * @param file 文件
     * @return 文件扩展名
     */
    public static String getExtension(MultipartFile file) {
        String extension = FileUtil.extName(file.getOriginalFilename());
        if (StringUtils.isEmpty(extension)) {
            extension = file.getContentType() != null ? file.getContentType().split("/")[1] : "";
        }
        return extension;
    }
}
